This invention is directed to a novel stent holder/compression instrument for holding and properly positioning a stent therein, in which the stent can be positioned and held without handling by an operator. The present invention is further directed to a novel method for positioning a stent within the novel stent holder/compression instrument. This invention is further directed to a novel instrument which can be used to ship a stent to a hospital and thereafter be used to crimp the stent onto a balloon catheter.
In order to improve the effectiveness of vascular angioplasty in relieving blockage or repairing cardiovascular damage, an expandable stainless steel mesh stent of tubular configuration has been developed for vascular implantation. The mesh stent is used to prevent arteries from closing (restenosis) after vascular balloon angioplasty. The stent is introduced into the artery by a balloon catheter on which the stent has been previously crimped and the stent is then dilated against the vascular implantation site by expansion of the balloon catheter. Precisely locating, implanting and expanding the stent requires that it be securely carried on the balloon catheter for both transport to the implantation site and expansion by the balloon.
A stent compression instrument is disclosed in U.S. patent application Ser. No. 08/745,317 which is commonly owned by the assignee herein, and employs a thin, elastomeric tubular diaphragm inside a housing to exert uniform forces on a stent to compress the stent onto and around a balloon catheter. The disclosure of said prior application is incorporated herein by reference. A stent in a neutral expanded state is placed over a balloon section of a catheter. The tubular diaphragm within the housing is expanded and the stent and balloon catheter are placed inside the diaphragm of the compression instrument. As pressurization forces are applied to the diaphragm, the stent is compressed and collapsed until the stent is rigidly and uniformly affixed to the balloon catheter. The stent loaded catheter is now ready for use and subsequent expansion of the stent by the catheter during implantation. This method requires handling of both the stent and the balloon catheter during the attachment or crimping procedure.
Improved stents with a delicate coating which enhances and improves the stent's efficacy are currently being tested and considered for use. The coatings could be damaged, by touching for example, during this handling phase.
The present invention provides a novel stent holder/compression instrument and method for attaching an expandable stent to a balloon catheter which eliminates the handling of the stent by an operator during attachment. The present invention also provides a novel instrument which can be used to ship a stent to a hospital and thereafter be used to crimp the stent onto a balloon catheter. Other features and advantages of the present invention will become apparent upon a reading of the attached specification in combination with an examination of the drawings.